1. Field of the Invention
The present invention relates generally to clutch release bearings, especially for automobile vehicles.
As is well known, a clutch release bearing generally comprises on the one hand an operating element which is controlled by a control element such as a clutch release fork, and, on the other hand, a driving element which is coupled axially to the operating element and which is intended to act on the declutching device of the clutch.
The present invention relates more particularly to clutch release bearings of the kind referred to as "pulled" bearings, which are designed to act in traction on the declutching device of the clutch, and which, in order to do this, must be coupled to the declutching device by their driving elements.
2. Description of the Related Art
For a coupling of this kind it has already been proposed e.g. in French Pat. No. 2 544 039, to permanently fasten to the declutching device of the clutch, a substantially annular piece, here for convenience referred to simply as a connecting piece, and to employ between this connecting piece and the driving element of the clutch release bearing, a coupling device adapted to provide for the desired coupling in at least one axial direction, i.e. that corresponding to the direction of traction.
Usually, and this is the case in French Pat. No. 2 544 039, this coupling device is fitted to the driving element of the clutch release bearing in advance and, to allow the axial engagement of this device with the connecting piece, the coupling device, which is disposed annularly around the axis of the assembly and at least partly engaged with an annular groove formed in the said driving element, is elastically radially deformable so that it can pass from a relatively retracted configuration, suitable to allow axial engagement, to a relatively opened out configuration suitable to enable the subsequent coupling to be effected.
In its simplest form it may be, for example, a metallic retaining ring open at a gap. Whatever the case, at rest, during storage of the clutch release bearing and during the manipulations which must be employed for its axial engagement with the coupling piece, it is normally, without exception, in the opened out configuration. Consequently, simply as a result of gravity, it then has an eccentric position relative to the axis of the assembly.
Because the coupling device thus projects axially in an accentuated manner from the side of the clutch release bearing there is the risk during storage, which is usually done in bulk, or during manipulation, that it will be subject to premature catching on other objects, and this may eventually cause its deterioration or even breakage.
Moreover, because during the axial engagement of the clutch release bearing with the connecting piece of the declutching device of the clutch it is an eccentric position, there is the risk that it will become misaligned during this axial engagement and consequently it will not be possible to complete this correctly, or without difficulty.
Finally, in order to take into account its eccentricity and to be able to receive it correctly with complete certainty, it is necessary that the connecting piece has an entry cone of which the approach diameter is at least equal to that corresponding to this eccentricity.
As this entry cone must also enable the coupling device to be squeezed sufficiently to be retracted in order to pass into the central opening of the connecting piece, it inevitably has an axial length which is the more significant the greater its approach diameter.
Besides this resulting in an expensive increase in the axial length of the connecting piece, and of the axial space occupied by this, the shaping, on this connecting piece of an entry cone having a relatively large axial length is itself troublesome and costly.
In addition it is known, and this is also the case in French Pat. No. 2 544 039 mentioned above, to provide for the use, between the clutch release bearing and the declutching device of the clutch to be controlled, of elastic means, hereinafter for convenience referred to simply as elastic bearing means, designed to bear axially on the declutching device whilst also bearing on the driving element of the clutch release bearing, continuously to maintain an elastic bearing between the declutching device and the coupling piece and thereby to avoid any noise from this region.
An object of the present invention is to provide an arrangement which, taking advantage of these elastic bearing means, enables the disadvantages set out above to be avoided and other advantages to be attained.